Transportation installation with a plurality of stations

ABSTRACT

A transportation installation having a lower substantially horizontal conveyor and a guide rail extending parallel to and spaced above the conveyor and a car transportable by the conveyor having a shoe frictionally engageable with the conveyor at its bottom, a guide wheel vertically movably mounted on its upper top end and means for moving the guide wheel upwardly into engagement with the guiderail during movement of the car by the conveyor. The installation includes at least one station to which the car may be switched from the conveyor, each of the stations including a carrier rail having an upstream portion parallel to and spaced below the guide rail, an intermediate portion which is spaced laterally and upwardly from the guide rail, a downstream portion which is parallel to and spaced below the guide rail, and connector portions extending convergently laterally outwardly and upwardly from the upstream and downstream portions to the upstream and downstream ends of the intermediate portions.

United States Patent Giraud TRANSPORTATION INSTALLATION WITH A PLURALITYOF STATIONS Inventor: Francois L. Giraud, Plaisir, France Assignee: LTVAerospace Corporation, Dallas,

Tex.

Filed: June 23, 1971 Appl. No.: 155,967

Foreign Application Priority Data July 6, 1970 France ..7024984References Cited UNITED STATES PATENTS Giraud 1 04/23 FS Juvinall..104/93 Larson ..104/130 Barthalon 104/89 Oct. 24, 1972 [57] ABSTRACT Atransportation installation having a lower substantially horizontalconveyor and a guide rail extending parallel to and spaced above theconveyor and a car transportable by the conveyor having a shoefrictionally engageable with the conveyor at its bottom, a guide wheelvertically movably mounted on its upper top end and means for moving theguide wheel upwardly into engagement with the guiderail during movementof the car by the conveyor. The installation includes at least onestation to which the car may be switched from the conveyor, each of thestations including a carrier rail having an upstream portion parallel toand spaced below the guide rail, an intermediate portion which is spacedlaterally and upwardly from the guide rail, a downstream portion whichis parallel to and spaced below the guide rail, and connector portionsextending convergently laterally outwardly and upwardly from theupstream and downstream portions to the upstream and downstream ends ofthe intermediate portions.

20 Claims, 4 Drawing Figures PATENTEUHCT 24 m2 SHEET 1 [IF 2 FRANCOIS L.GIRAUD INVENTOR BY W A TOR EY PATENTEDHBI 24 I972 SHEEI 2 BF 2 FRANCOISL. GIRAUD INVENTO BY 4 A N Y TRANSPORTATION INSTALLATION WITH APLURALITY OF STATIONS The present invention relates to a transportationinstallation, particularly for passengers.

There are numerous applications for transportation installations,particularly for passengers, which make it possible to serve arelatively large number of stations, situated at average distances fromone another; as nonlimiting examples of these applications, there areurban and suburban transportation systems, the service of variouspavilions at an exposition or of the various locations of a technical oradministrative center, etc.

All these applications necessitate transportation installations having ahigh traffic capacity, high frequency of service of each of thestations, as well as the possibility of selective service of eachstation of the installation from any other station. The latter conditionis particularly difficult to meet because at any given moment and in agiven station in the installation, the number of passengers wishing togo to another station in the installation is relatively small, in directproportion to the number of stations in the installation and providedthat the traffic is distributed in a substantially uniform manner amongthem. This problem can be solved by equipping the passengertransportation installation with a large number of vehicles, each ofsmall capacity and capable of being moved from any station in theinstallation toward another freely chosen station. But, although the useof small-capacity vehicles, i.e., designed, for example, for two or fourpassengers only, offers the great advantage of a substantial reductionin the time necessary to unload and reload each vehicle in each station,this is incompatible with the obtention of high traffic capacity exceptinsofar as the vehicles, independently of one another (i.e., notcoupled), follow one another on the main track of the said installationat very short intervals, corresponding, for example, to a period ofseveral seconds. The embodiment of a transportation installation of thetype mentioned, having high traffic capacity, therefore raises theproblem which is technically very difficult to solve, of the temporaryand selective stopping at selected stations of the installation of someof the many vehicles following one another at very short intervals onthe main track of the said installation. If each station of theinstallation is served, for example, by a special side or secondarytrack connected to the main track, the said problem is one of selectiveshunting or switching toward some of the side tracks of the installationof certain of the many vehicles following one another at very shortintervals on the main track; in other words, it is a matter of a problemof selective switching at a very fast rate. A technical solution of thisproblem cannot be conceived of unless the instantaneous positions of thevarious vehicles on the main track of the installation are defined withvery great precision, i.e., in particular, with an error much smallerthan the interval provided between the various, successive vehicles,which also implies an equally high precision as to the instantaneousspeed of the various vehicles. Moreover, the use of vehicles of smallcapacity, hence of relatively small size, does not make it easy to equipthem with a selfcontained source of energy which would verysubstantially increase their bulk, weight and cost.

The transportation installation according to the present invention makesit possible to solve all the problems and meet all the conditionsindicated above under the best conditions of technical simplicity andprofitability. It is characterized in that it comprises a main trackwhich is formed essentially by a conveyor, placed on the ground, and bya guide rail supported at a generally constant distance D above the saidconveyor, side or secondary tracks, each of which serves a station andis formed essentially by a carrier rail passing below the guide rail ofthe main track, in an incoming switching zone, and an outgoing switchingzone, where the carrier rail is supported at a distance d, less than thedistance D, above the conveyor, while in the sections of each secondaryor side track, the carrier rail is supported at a distance greater thanthe distance d above the ground, as well as passive vehicles which canrest by means of at least one lower shoe on the conveyor of the maintrack, and which are each equipped at the top with at least one wheel ofradius R which is less than (D d 2, and of means for varying in aswitching zone the distance from the axle of this wheel to the shoe ofthe vehicle, between the two values (D R) and (d +r).

Since the main track of the transportation installation according to thepresent invention is constituted essentially by a conveyor of knowntype, of a belt, cable, chain or other suitable type, the speed of whichcan easily be kept constant and largely independent of the load on thesaid conveyor, the instantaneous positions and speeds of the vehicleswhich it entrains are always defined with sufficiently high precision toeliminate any error in the selective switching of the vehicles from thesaid conveyor to the secondary or side tracks serving the variousstations of the installation, even in the event the said vehicles followone another on the conveyor at small enough intervals to obtain a hightraffic capacity. The transportation installation according to thepresent invention can therefore be equipped with a relatively highnumber of vehicles of small capacity, hence of small size, whosestopping times at the stations can consequently be very brief. The useof a conveyor to constitute the main track of the transportationinstallation according to the present invention offers the additionaladvantage of permitting the accommodation of exclusively passivevehicles without any self-contained source of energy capable ofincreasing the size, weight and cost of each vehicle.

In a preferred form of embodiment of the transportation installationaccording to the invention, the means with which each vehicle isequipped to vary the distance from the axle of the upper wheel to thelower shoe, comprise a set of communicating, elastic bellows by means ofwhich the said axle is suspended from a pylon solid with the upper partof the vehicle, as well as means for varying the expansion of the saidelastic bellows, in particular their degree of filling by a fluid underpressure. Each vehicle preferably comprises at least one variablechamber in controllable communication with the set of suspensionbellows, and subjected to an action of a compression by an elasticmeans, as well as means for temporarily opening in a switching zone, thecommunication between the said variable capacity chamber and the saidset of suspension bellows; the variable chamber is constituted by anauxiliary bellows mounted on a fixed part of the vehicle and subjectedto the action of a compression spring; finally, the variable chamber canbe connected to the set of suspension bellows by two pipes, in which areinserted, respectively, two control valves and two check valves withmutually opposing directions of flow, and means are provided to open, ina switching zone, one of the two control valves, and close the other.

The use of passive vehicles in the transportation installation accordingto the present invention, raises however the problem of controlling themon the secondary track serving each station, with a view in particularto stopping them at the corresponding station, then starting them upagain and accelerating them toward the outgoing switching zone wherethey must reach the speed of the conveyor in order to be switched towardthe latter; this problem is solved in a particularly advantageousfashion in a preferred form of embodiment of the transportationinstallation according to the invention, in which each vehicle isequipped with a device for braking its wheel, in particular on thecarrier rail of a secondary track, in order to stop the vehicle at thecorresponding station; in this case, preferably, the brake device ofeach vehicle, of hydraulic or pneumatic type, is fed from the set ofsuspension bellows, where, during the braking on the carrier rail of aside track, a maximum pressure prevails that is substantiallyproportional to the loaded weight of the vehicle. Thanks to the latterarrangement, the action of the brakes of each vehicle engaged on a sidetrack is always proportional to the pressure prevailing in the set ofsuspension bellows; in other words, the braking power on the vehiclewheel is always proportional to the weight of the loaded vehicle, sothat decelerations of the said vehicle on the side track can be renderedlargely independent of its working load. In a variant, at least one ofthe side tracks can comprise, before the corresponding station, means tobrake the wheel of the vehicle to be stopped at the said station, thesemeans including for example, a rising ramp and/or a track brake.Moreover, each of the side tracks must comprise, beyond thecorresponding station, means for accelerating the vehicle stopped at thesaid station, up to the speed of the conveyor. The latter means can be,for example, a descending ramp, formed by the carrier rail of the sidetrack considered.

Furthermore, the carrier rail of each side track can have, before theoutlet of its incoming shunting zone, a rising ramp which causes thevehicle to rise above the conveyor of the main track; naturally, thisrising ramp can be proportioned to produce at least partial braking ofthe vehicle which is necessary in order to stop it at the station servedby the considered side track. Likewise, the carrier rail of eachsecondary track has to form, somewhat beyond the entrance to itsswitching zone, a descending ramp to bring back down to the level of theconveyor of the main track each vehicle emerging from the station servedby the side track considered; naturally, this descending ramp canlikewise be proportioned so as to accelerate the vehicle to the speed ofthe conveyor.

A form of embodiment of a passenger transportation installationaccording to the present invention has been described below andillustrated schematically in the attached drawing.

FIG. 1 represents schematically, in perspective, the incoming switchingzone of the secondary or side track serving one station of thetransportation installation.

FIG. 2 represents, in a plane perpendicular to the tracks in FIG. 1, thevarious phases in the switching of a vehicle from the conveyorconstituting the main track toward the said side track.

FIG. 3 is a partial view in the direction of arrow Ill in FIG. 2a.

FIG. 4 is a schematic view illustrating the working of the incomingswitching zone represented in FIG. 1.

The passenger transportation installation according to the presentinvention comprises a main track, which is formed essentially by aconveyor 1, (FIG. I), placed on the ground, and by a guide rail 2,supported, for example, by pylons 3, suitably spaced at a distance D,which generally is constant, above the conveyor 1. The conveyor 1 ispreferably of a known type, such as a belt, cable or chain type, or someother suitable type. Along the main track of this transportationinstallation and somewhat removed from this main track, stations (notshown) are disposed, each of which is served from the said main track bya secondary track diverging from the main track into a first switchingzone known as the incoming switching zone, then passes to thecorresponding station, and finally converges with the main track in asecond, so-called outgoing zone. FIG. 1 which represents an incomingswitching or shunting zone, shows that each switching track is formedessentially by a carrier rail 4 which, in each of the two secondaryzones, is supported, for example, by the same pylons as the guide rail 2of the main track, or by special pylons at a distance d, less than thedistance D, above conveyor 1, i.e., below the said guide rail 2; in thesections of each side track other than its two switching zones, hence inparticular in the passage through the corresponding station, the carrierrail 4 is supported, for example, by pylons S at a distance greater thand above the ground. The transportation installation according to thepresent invention also comprises passive vehicles 6, i.e., vehicleswithout a selfcontained source of energy, which are adapted to cooperatesometimes with the main track and sometimes with the side track servingone of the stations of the installation; since each of the passivevehicles 6 is made in a small capacity, (for example for two or fourpassengers only), it can be of a relatively small size, light weight andlow cost, which is particularly advantageous to the embodiment oftransportation installations with high traffic capacity comprising alarge number of small vehicles of this type. In the said form a ofembodiment of the invention, each vehicle 6 is equipped at the bottomwith a shoe 7 by means of which it can rest in particular on conveyor 1of the main track, and is equipped at the top with a wheel 8 whoseradius R is less than (D d)/2; according to the present invention, meansare provided to vary, particularly in a switching zone, the distancefrom the axle of wheel 8 of each vehicle to its shoe 7, between thevalues (D R) and (d+R). In the case of the said form of embodiment ofthe invention, the means for varying the distance from the axle of wheel8 of each vehicle to the shoe 7 are embodied as follows: as seen inFIGS. 2 and 3, the axle of wheel 8 is mounted on a support 10, forexample in the form a plate, which is itself suspended from the upperend of pylon or bracket 9 by a set of communicating bellows 11, filledwith a fluid under pressure; in this form of embodiment, this set ofcommunicating bellows comprises a single pair of bellows aligned in thedirection of movement of the vehicle, and a choke can be provided, inknown fashion, in the communication between these two bellows (thiscommunication, as well as the corresponding choke, have not been shown,in order not to complicate the figure); coil or leaf springs, also notshown, can optionally be provided between the support and the upper endof bracket 9, so as to compress the set of be]- lows 11. Furthermore, avariable chamber, constituted essentially by an auxiliary bellows 12(FIG. 2) is mounted on a fixed part of the vehicle, for example, onbracket 9, so as to be subjected to the action of a compression spring13; the variable chamber 12 is connected to the set of bellows 11 by twopipes 14a and 14b, in each of which is inserted a control valve 15a or15b and a check valve 16a or 16b; the two check valves 16a and 16b aremounted in such a way as to have mutually opposing directions ofpassage, as indicated by the arrowhead symbols which represent thesecheck valves diagrammatically in FIG. 2a; furthermore, the two controlvalves 15a and 15b are coupled to one another by known means whichtherefore need not be described and which have simply been symbolized bya dotted connecting line, so that one of the two control valves 15a and15b is always in open position, and the other is closed, as representedin FIG. 2a. Naturally the coupling of the two control valves 15a and15b, each of which is a two-way valve, can be embodied by combining theminto a single control valve with at least three passages. The set ofsuspension bellows 11, as well as auxiliary bellows 12, contains a totalvolume of fluid under pressure that is less than the sum of maximumvolumes. Finally, means are provided to open, in a shunting zone,preferably automatically, one of the two control valves 15a and 15b,consequently, to close the other.

Each of the passive vehicles 6 of the said transportation installationis equipped with a device (not shown) to brake its wheel 8; it can be amatter of a braking device of known type, hydraulic or pneumatic, whichtherefore need not be described in detail; preferably, this brakingdevice, with which each vehicle is equipped, is fed from the set ofsuspension bellows 11, through a suitable duct (not shown), eitherdirectly, in the event the braking device can be fed by the same fluidunder pressure as the set of suspension bellows, or through a suitableconverter device, optionally of known type, in the event the brake fluidis different from the fluid filling the set of suspension bellows.Moreover, carrier rail 4 of each secondary track can form a rising ramp(17 in FIG. 4) somewhat before the outlet from its incoming shuntingzone, so that beyond the outlet of the incoming switching zone, carrierrail 4 of the side track is supported (by pylons similar to 5 in FIG.1), at a distance above the ground greater than d, which the saidcarrier rail retains up to a point close to the outlet from the stationserved by the said side track; below this station, the carrier rail ofthe side track forms a descending ramp which returns the said carrierrail to the entrance of the outgoing shunting zone, at a distance abovethe ground, and hence above conveyor 1, which is exactly equal to d.

The passenger transportation installation according to the presentinvention, as just described, works as follows:

Between two successive stations of the installation, the passivevehicles rest, at regular intervals, each with the under face of itslower shoe 7 on the top face of conveyor 1 of the main track whichentrains them at uniform speed; and since control valve 15a of the twovalves 15a, 15b, is closed, which would optionally permit auxiliarybellows 12 to empty into the set of suspension bellows 1 1, throughcheck valve 16a, while control valve 15b is open, which permitted theset of suspension bellows 11 to empty into auxiliary bellows 12, thelatter is at maximum extension; while the set of bellows 11 iscompressed by the aforementioned elastic parts (not shown), so thatsupport 10, on which the axle of wheel 8 is mounted applies the top ofthe rim of this wheel 8 against the running surface facing downward ofguide rail 2. This situation is illustrated in FIG. 2a, whichcorresponds to the passage of vehicle 6 at point a in FIG. 2. Naturally,the braking device for wheel 8 of vehicle 6 is then released, so thatthe wheel can rotate in contact with guide rail 2. When a vehicle 6,entrained by conveyor 1, reaches the upper end b of the incomingshunting zone of a side track serving a station of the installation, acomparator (not shown), fixed for example to the lower shoe 7 of vehicle6, or to its pylon or bracket 9, compares the coded indication of thecorresponding station, which is born by a suitable part (not shown),fixed close to one edge of conveyor 1, or close to one of the rails 2and 4, for example on one of the pylons 3, with a coded indication ofthe destination of vehicle 6, which was, for example, selected by thepassenger or passengers, using known means which need not be described.If the indication of the destination selected by the passengers, on theone hand, and the code of the station, on the other coincide, the saidcomparator produces a signal, an electric one, for example, which istransmitted to a device, an electromagnetic one for example, controllingvalves 15a and 15b, cou{ pled to one another, so as to open the firstand close the second; consequently, auxiliary bellows 12 is emptied,partially and gradually into the set of suspension bellows 11, under theinfluence of compression spring 13; the result is a gradual expansion ofthe set of suspension bellows l1, and consequently a gradual descent ofsupport 10 on which the axle of wheel 8 is mounted, the whole beingproportioned in such a way that when bellows 11 and 12 have exchangedtheir respective states of maximum and minimum fullness, the bottom ofthe rim of wheel 8, guided by lateral parts and 18b (FIG. 2, b 0) comesin contact with the upper running surface of carrier rail 4 of the sidetrack considered (the case illustrated in FIG. 20, which corresponds tothe passing of the vehicle at point 0 in FIG. 1), the said wheel 8,naturally, ceasing to cooperate with guide rail 2 of the main track,although vehicle 6 does not cease to rest with shoe 7 on conveyor 1 ofthe main track. Since wheel 8 of vehicle 6 now begins to climb ramp 17formed by carrier rail 4, the lower shoe 7 of the said vehicle isgradually raised above conveyor 1 of the main track, as can be seen inFIG. 2d and 4; between points d and e in FIG. 1, correspondingrespectively to parts d and e in FIG. 2, the carrier rail 4 of the sidetrack considered diverges from the vertical plane v passing through thecenters of the guide rail 2 and the conveyor 1; furthermore, as seen inFIG. 4, at the exit from rising ramp 17, carrier rail 4 of the sidetrack is supported, for example, by pylon (not shown in FIG. 4)

at a distance d it above the ground, such that the lower shoe 7 ofvehicle 6 passes largely above all the 'ir-' regularities of the ground;the slope of rising ramp 17 formed by carrier rail 4 is preferablyselected so that each vehicle 6, at the top of ramp 17 will have a speedsubstantially less than its speed of entrainment by conveyor 1, andstill just enough to bring the vehicle into the station (not shown)served by the said side track; in this station, automatic means, ofwhich there are numerous known forms of embodiment, hence it isunnecessary either to describe or represent them, cause the applicationof the braking device of wheel 8 on vehicle 6, and stop the latter inthe station, with a view to its unloading and perhaps reloading. In theform of embodiment considered, in which the braking device for thevehicle is fed from the set of suspension bellows 1 l, in which at thistime a maximum pressure, substantially proportional to the loaded weightof the vehicle, prevails, the application of this braking device issuitable retarded, with respect to the moment when the set of suspensionbellows 11 reaches its state of maximum fullness, for example, by theinsertion of known retarding devices or chokes in the duct (not shown)connecting the said set of suspension bellows 11 to the braking device.Means which are likewise automatic and, optionally, known, can likewisebe provided in each station which, after release of the brake on thestopped and reloaded vehicle, push the said vehicle to the top of thedescending ramp provided near the exit from the said station; thisdescending ramp is preferably proportioned so that the passive vehicle6, after having run freely with its wheel 8 on the carrier rail 4 beyondthe said station, reaches the entry of the outgoing switching zone ofthe corresponding secondary or side track with a speed that ispreferably very close to that of conveyor 1- of the main track, and at aheight above the ground selected so that the lower shoe of vehicle 6will rest on the upper face of the said conveyor 1 without having upperwheel 8 cease to work with the carrier rail (as in FIG. 20). Theautomatic means already mentioned and not shown, then cause the reversalof the positions of the two control valves a and 15b, so that theelastic parts acting on the set of suspension bellows 11 will cause thepartial and gradual emptying of the latter into the fixed supplementarybellows 12 through check valve 16b and control valve 15b, now open; thecompression of the set of suspension bellows 11 causes, with the aid ofsupport 10 of the axle of wheel 8, the rise of the latter, back into theposition in which it works with the running surface of the guide rail 2of the main track (as in FIG. 2a). Naturally, the switching of thepassive vehicle 6 from the side track under consideration toward themain track takes place in very gentle fashion, without jolting oracceleration which can be unpleasant to the passengers because thevehicle is propelled at a speed very close to that of the conveyor ofthe main track, when its lower shoe 7 comes to rest on the upper face ofthe said conveyor. Likewise, in the course of the braking phase of thevehicle, for stopping it in a station, the same advantages are obtained,not only thanks to the use of a very gradual braking device, but thanksalso to the fact that the latter is fed from the set of suspensionbellows in which the pressure prevailing therein is then substantiallyproportional to the loaded weight of the vehicle, so as to obtain abraking power exactly matched to this loaded weight. When the passivevehicle is running on the carrier rail of a side track, its twosuspension bellows 11 aligned in the direction of movement of thevehicle, and communicating by means of a choke, compensate for theeffects of pitching due to irregularities that may be present in theside track and the carrier rail. in each outgoing switching zone,lateral guide parts facing downward, the function of which is similar tothat of lateral guide parts 18a and 18b in FIG. 2b, can be providedsomewhat before the exit from this switching I zone, on the guide railor the main track.

The form of embodiment of the transportation installation according tohe present invention just described, can be varied in many ways, some ofwhich are obvious to the man of the art, and all of which come withinthe scope of the invention. A few of these variants will be indicatedbelow. The running tracks serving the various stations of theinstallation can form closed loops, each passing through thecorresponding station, and tangent to the main track in a single zone,the upstream part of which (in the direction of movement of the conveyorof the said main line) serves as an incoming switching zone, and thelower part, as an outgoing switching zone. At least one of the guiderails of the main track and the carrier rail of each side track can bealigned with another parallel rail; the two parallel rails can besupported in the same vertical plane, one of them being eliminated ineach switching zone; likewise, there can be two continuous parallelrails, supported in the same horizontal plane, i.e., substantiallyparallel to the ground, in which case each passive vehicle must have atleast two vertical wheels to cooperate, respectively, with the twoparallel rails. However, even in the case of single rails, each passivevehicle 6 can be equipped with a plurality of vertical wheels, alignedin the direction of movement of the vehicle, and mounted, for example,on a support in the form of a single plate suspended from the upper endof the upper bracket of the vehicle by a single set of suspensionbellows. The set formed by two suspension bellows aligned in thedirection of movement of the vehicle described above, can becomplemented by two additional suspension bellows alignedperpendicularly to the direction of movement of the vehicle, andserving, in particular, to compensate for the rolling effects to whichthe said vehicle can be subjected when it is running on the carrier railof a side track; these two supplementary suspension bellows must thencommunicate with one another, and optionally with the two principalsuspension bellows, preferably through chokes. The means for varying thedistance from the axle of each wheel of the passive vehicles of theinstallation, to their shoe, can differ widely from those describedabove; in particular, the wheel of the vehicle can be suspended from theupper and lower branches of a fork formed by the free upper end of thebracket solid with the top of the vehicle, with the aid, respectively,of two sets of bellows with controllable communication, containing atotal volume of fluid under pressure that is less than the sum of theirmaximum volumes, means being provided to temporarily open thecommunication between the two sets of bellows in a switching zone so asto cause the partial emptying of the fuller set of bellows into theemptier set of bellows and consequently, the exchange of the respectiveupper and lower working positions of the wheel of the vehicle with theguide rail of the main track and the carrier rail of a side track,according to the patent application filed by Francois Giraud, andentitled, Transportation installation, particularly for passengers andfiled the same date as this application. In the latter case, each of thetwo sets of bellows can be embodied in one of the ways described for thesingle set of bellows 11 (FIG. 2). The exchange between the two workingpositions of the wheel of each vehicle can, of course, also be obtainedby purely mechanical or electromechanical means, optionally known ones.The means with which each vehicle of the installation according to thepresent invention is equipped for establishing and controllingcommunication between the various bellows when said vehicle is in aswitching zone, can themselves be embodied in diverse ways which candiffer from the one described above; the same is true of the automaticmeans, mentioned above, for operating the valves controlling the saidcommunications. Moreover, the rising and descending ramps providedrespectively somewhat before the exit from each incoming switching orshunting zone and somewhat beyond the entrance to each outgoingswitching zone, can be proportioned merely as a function of the need tovary, in the said switching zones, the position of the lower shoe ofeach vehicle with respect to the conveyor of the main track. In thelatter case, the stopping of each vehicle at a station can be insuredpractically exclusively by braking its wheel or wheels; it is alsopossible, however, to equip the carrier rail of each side track with atrack brake, above the corresponding station, which can optionally allowthe elimination of the braking device on each vehicle. Likewise, eachvehicle stopped at a station can be accelerated between the exit fromthis station and the corresponding outgoing switching zone, so as toreach therein a speed practically equal to that of the conveyor, bymeans different from an ascending ramp and optionally combined with theside track, in particular with its carrying rail. One of these means,described in the patent application cited above, includes a departureconveyor belt, moving at the speed of the conveyor, from the stationunder consideration to the corresponding outgoing switching zone, andeach vehicle comprises, at the level of its lower shoe,controlled-friction clutching means allowing a gradual variation of therelative speed of the vehicle with respect to the said conveyor beltbetween a maximum value for which the vehicle is stopped in thecorresponding station and a zero value for which the vehicle isentrained by the conveyor belt at the speed of the conveyor toward theoutgoing switching zone. In a preferred form of embodiment, thecontrolled-friction clutching means consist essentially of an endlessbelt guided to pass between the lower shoe of the vehicle and thedeparture conveyor belt or the conveyor on which the said vehicle rests,as well as a device for gradually braking the movement communicated tothe said endless belt by the departure conveyor belt.

While only one embodiment of the invention, together with modificationsthereof, has been described in detail herein and shown in theaccompanying drawing, it will be evident that various furthermodifications are possible in the arrangement and construction of itscomponents without departing from the scope of the invention.

What is claimed is:

1. Transportation installation, particularly for passengers,characterized in that it comprises a main track, which is formedessentially by a conveyor placed on the ground, and by a guide railsupported at a distance D, which is generally constant, above the saidconveyor, secondary or side tracks, each one of which serves a stationand is formed essentially by a carrier rail, passing below the guiderail of the main track, in an incoming switching or shunting zone and anoutgoing shunting zone, where the carrier rail is supported at adistance d, less than D, above the conveyor, while the other sections ofeach side track, the carrier rail is supported at a distance greaterthan d above the ground, as well as passive vehicles which can rest bymeans of at least one lower shoe on the conveyor of the main track, andeach of which is equipped, at the top, with at least one wheel of radiusR less than (D-d)/2, and with means for varying, in a shunting zone, thedistance from the axle of this wheel of the vehicle to the shoe, betweenthe two values (D- R) and (d +R).

2. Transportation installation according to claim 1, characterized inthat the conveyor of the main track is of a known type, using belt,cable or chain, or of a suitable different type.

3. Transportation installation according to claim 1, characterized inthat the means with which each vehicle is equipped for varying thedistance from the axle of its upper wheel to its lower shoe, include atleast one set of communicating, elastic bellows, by means of which thesaid axle is suspended from a bracket, solid with the upper part of thevehicle, as well as means for varying the expansion of the said elasticbellows, in particular their degree of filling by a fluid underpressure.

4. Installation according to claim 3, characterized in that each vehiclecomprises at least one variable chamber in controllable communicationwith the set of suspension bellows, and subjected to an action ofcompression by an elastic means, as well as means for temporarilyopening, in a shunting zone, the communication between the said variablechamber and the said set of suspension bellows.

5. Installation according to claim 4, characterized in that the variablechamber is constituted essentially by an auxiliary bellows, mounted on afixed part of the vehicle, and subjected to the action of a compressionspring.

6. Installation according to claim 4, characterized in that the variablechamber is connected to the set of suspension bellows by two pipes inwhich there are inserted, respectively, two control valves and two checkvalves having mutually opposing direction of flow, and in that means areprovided to open one of the two control valves, and close the other, ina shunting zone.

7. Installation according to claim 1, characterized in that the carrierrail of each side track forms a rising ramp somewhat before the outletof the incoming shunting zone, and a descending ramp somewhat beyond theentrance to the outgoing shunting zone.

8. Installation according to claim 1, characterized in that the carrierrail of the side track is equipped, at the entrance to the incomingshunting zone, with lateral guide parts, facing upward, while the guiderail of the main track is equipped, somewhat beyond the outlet of theoutgoing shunting zone, with lateral guide parts facing downward.

9. Installation according to claim 1, characterized in that each vehicleis equipped with a device for braking its wheel, in particular on thecarrier rail of a side track, in order to stop the vehicle at thecorresponding station.

10. Installation according to claims 3 and 9, characterized in that thebraking device of each vehicle, of the hydraulic or pneumatic type, isfed from the set of suspension bellows where, during the braking on thecarrying rail of a side track, a maximum pressure prevails,substantially proportional to the loaded weight of the vehicle.

1 1. Installation according to to one of claims 1 and 7, characterizedin that at least one of the side tracks comprises, before thecorresponding station, means to brake the wheel of the vehicle to bestopped at the said station, these means comprising, for example, arising ramp and/or a track brake.

12. installation according to one of claims 1 and 7, characterized inthat each of the side tracks comprises, beyond the correspondingstation, means, for example, a descending ramp, to accelerate thevehicle, stopped at the said station, up to the speed of the conveyor.

13. Installation according to claim 12, characterized in that the meanswith which each of the side tracks is equipped in order to accelerate avehicle up to the speed of the conveyor, comprise a departure conveyorbelt, moving at the speed of the conveyor, from the correspondingstation to the outgoing shunting zone, and that each vehicle comprises,at the level of the lower shoe, controlled-friction clutch means, forgradually varying the relative speed of the vehicle with respect to thesaid conveyor belt, between a maximum value, at which the vehicle isstopped in the corresponding station, and a zero value at which thevehicle is entrained by the conveyor belt at the speed of the conveyor,toward the outgoing shunting zone.

14. Installation according to claim 13, characterized in that thecontrolled-friction clutch consists, essentially of an endless belt,guided to pass between the lower shoe of the vehicle and the departureconveyor belt, or the conveyor in which the said vehicle is resting, aswell as a device for gradually braking the movement communicated to thesaid endless belt, by the departure conveyor belt.

15. A transportation installation including: a lower substantiallyhorizontal conveyor; a guide rail extending parallel to and spaced abovethe conveyor; and at least one station comprising a carrier rail havingan upstream portion parallel to and spaced below the guide rail, anintermediate portion spaced laterally and upwardly from the guide rail,a downstream portion extending parallel to and spaced below the guiderail, and connector portions extending convergently upwardly andoutwardly from the upstream and downstream portions of the carrier railto the upstream and downstream ends of the intermediate portion; and acar transportable by said conveyor, said car having support means at itsbottom engageable with said conveyor, a guide wheel vertically movablymounted at the upper end of the car, and means for moving the guidewheel upwardly into engagement with the guide rail during movement ofthe car by the conveyor and downwardly into position engaging saidcarrier rail for raising the car out of engagement with the conveyor andfor movement on the carrier rail.

16. The transportation installation of claim 15, wherein said means formovably mounting said guide wheel on said car includes a bellows means,and said third means includes a source of fluid under pressure, conduitmeans connecting said source of fluid under pressure with said bellows,and valve means connected to said conduit means for selectivelypermitting flow of fluid under pressure to said bellows from said sourceof fluid and from said bellows to said source.

17. The installation of claim 16, wherein said source of fluid underpressure comprises means providing a variable capacity chamber and meansyieldably biasing said chamber toward a contracted position.

18. A car for use in a transportation installation having a lowersubstantially horizontal conveyor, a guide rail extending parallel toand spaced above the conveyor and a carrier rail spaced below said guiderail, said car including: a support means at its bottom en gageable witha lower horizontal conveyor of a transportation installation, a guidewheel vertically movably mounted on the upper end of the car, and meansfor moving the guide wheel upwardly to a position wherein it isengageable with the guide rail during movement of the car by the lowerhorizontal conveyor and downwardly into position engageable with saidcarrier rail for raising the car out of engagement with the carrier andfor movement on the carrier rail.

19. The car of claim 18, wherein said means for movably mounting saidguide wheel on said car includes a bellows means, and said third meansincludes a source of fluid under pressure, conduit means connecting saidsource of fluid under pressure with said bellows means, and valve meansconnected to said conduit means for selectively permitting flow of fluidunder pressure to said bellows from said source of fluid and from saidbellows to said source.

20. The installation of claim 19, wherein said source of fluid underpressure comprises means providing a variable capacity chamber and meansyieldably biasing said chamber towards a contracted position.

1. Transportation installation, particularly for passengers, characterized in that it comprises a main track, which is formed essentially by a conveyor placed on the ground, and by a guide rail supported at a distance D, which is generally constant, above the said conveyor, secondary or side tracks, each one of which serves a station and is formed essentially by a carrier rail, passing below the guide rail of the main track, in an incoming switching or shunting zone and an outgoing shunting zone, where the carrier rail is supported at a distance d, less than D, above the conveyor, while the other sections of each side track, the carrier rail is supported at a distance greater than d above the ground, as well as passive vehicles which can rest by means of at least one lower shoe on the conveyor of the main track, and each of which is equipped, at the top, with at least one wheel of radius R less than (D-d)/2, and with means for varying, in a shunting zone, the distance from the axle of this wheel of the vehicle to the shoe, between the two values (D - R) and (d + R).
 2. Transportation installation according to claim 1, characterized in that the conveyor of the main track is of a known type, using belt, cable or chain, or of a suitable different type.
 3. Transportation installation according to claim 1, characterized in that the means with which each vehicle is equipped for varying the distance from the axle of its upper wheel to its lower shoe, include at least one set of communicating, elastic bellows, by means of which the said axle is suspended from a bracket, solid with the upper part of the vehicle, as well as means for varying the expansion of the said elastic bellows, in particular their degree of filling by a fluid under pressure.
 4. Installation according to claim 3, characterized in that each vehicle comprises at least one variable chamber in controllable communication with the set of suspension bellows, and subjected to an action of compression by an elastic means, as well as means for temporarily opening, in a shunting zone, the communication between the said variable chamber and the said set of suspension bellows.
 5. Installation according to claim 4, characterized in that the variable chamber is constituted essentially by an auxiliary bellows, mounted on a fixed part of the vehicle, and subjected to the action of a compression spring.
 6. Installation according to claim 4, characterized in that the variable cHamber is connected to the set of suspension bellows by two pipes in which there are inserted, respectively, two control valves and two check valves having mutually opposing direction of flow, and in that means are provided to open one of the two control valves, and close the other, in a shunting zone.
 7. Installation according to claim 1, characterized in that the carrier rail of each side track forms a rising ramp somewhat before the outlet of the incoming shunting zone, and a descending ramp somewhat beyond the entrance to the outgoing shunting zone.
 8. Installation according to claim 1, characterized in that the carrier rail of the side track is equipped, at the entrance to the incoming shunting zone, with lateral guide parts, facing upward, while the guide rail of the main track is equipped, somewhat beyond the outlet of the outgoing shunting zone, with lateral guide parts facing downward.
 9. Installation according to claim 1, characterized in that each vehicle is equipped with a device for braking its wheel, in particular on the carrier rail of a side track, in order to stop the vehicle at the corresponding station.
 10. Installation according to claims 3 and 9, characterized in that the braking device of each vehicle, of the hydraulic or pneumatic type, is fed from the set of suspension bellows where, during the braking on the carrying rail of a side track, a maximum pressure prevails, substantially proportional to the loaded weight of the vehicle.
 11. Installation according to to one of claims 1 and 7, characterized in that at least one of the side tracks comprises, before the corresponding station, means to brake the wheel of the vehicle to be stopped at the said station, these means comprising, for example, a rising ramp and/or a track brake.
 12. Installation according to one of claims 1 and 7, characterized in that each of the side tracks comprises, beyond the corresponding station, means, for example, a descending ramp, to accelerate the vehicle, stopped at the said station, up to the speed of the conveyor.
 13. Installation according to claim 12, characterized in that the means with which each of the side tracks is equipped in order to accelerate a vehicle up to the speed of the conveyor, comprise a departure conveyor belt, moving at the speed of the conveyor, from the corresponding station to the outgoing shunting zone, and that each vehicle comprises, at the level of the lower shoe, controlled-friction clutch means, for gradually varying the relative speed of the vehicle with respect to the said conveyor belt, between a maximum value, at which the vehicle is stopped in the corresponding station, and a zero value at which the vehicle is entrained by the conveyor belt at the speed of the conveyor, toward the outgoing shunting zone.
 14. Installation according to claim 13, characterized in that the controlled-friction clutch consists, essentially of an endless belt, guided to pass between the lower shoe of the vehicle and the departure conveyor belt, or the conveyor in which the said vehicle is resting, as well as a device for gradually braking the movement communicated to the said endless belt, by the departure conveyor belt.
 15. A transportation installation including: a lower substantially horizontal conveyor; a guide rail extending parallel to and spaced above the conveyor; and at least one station comprising a carrier rail having an upstream portion parallel to and spaced below the guide rail, an intermediate portion spaced laterally and upwardly from the guide rail, a downstream portion extending parallel to and spaced below the guide rail, and connector portions extending convergently upwardly and outwardly from the upstream and downstream portions of the carrier rail to the upstream and downstream ends of the intermediate portion; and a car transportable by said conveyor, said car having support means at its bottom engageable with said conveyor, a guide wheel vertically movably mounted at the upper end of the car, and means for moving the guide wheel upwardly into engagement with the guide rail during movement of the car by the conveyor and downwardly into position engaging said carrier rail for raising the car out of engagement with the conveyor and for movement on the carrier rail.
 16. The transportation installation of claim 15, wherein said means for movably mounting said guide wheel on said car includes a bellows means, and said third means includes a source of fluid under pressure, conduit means connecting said source of fluid under pressure with said bellows, and valve means connected to said conduit means for selectively permitting flow of fluid under pressure to said bellows from said source of fluid and from said bellows to said source.
 17. The installation of claim 16, wherein said source of fluid under pressure comprises means providing a variable capacity chamber and means yieldably biasing said chamber toward a contracted position.
 18. A car for use in a transportation installation having a lower substantially horizontal conveyor, a guide rail extending parallel to and spaced above the conveyor and a carrier rail spaced below said guide rail, said car including: a support means at its bottom engageable with a lower horizontal conveyor of a transportation installation, a guide wheel vertically movably mounted on the upper end of the car, and means for moving the guide wheel upwardly to a position wherein it is engageable with the guide rail during movement of the car by the lower horizontal conveyor and downwardly into position engageable with said carrier rail for raising the car out of engagement with the carrier and for movement on the carrier rail.
 19. The car of claim 18, wherein said means for movably mounting said guide wheel on said car includes a bellows means, and said third means includes a source of fluid under pressure, conduit means connecting said source of fluid under pressure with said bellows means, and valve means connected to said conduit means for selectively permitting flow of fluid under pressure to said bellows from said source of fluid and from said bellows to said source.
 20. The installation of claim 19, wherein said source of fluid under pressure comprises means providing a variable capacity chamber and means yieldably biasing said chamber towards a contracted position. 